NAME

DBI::Changes - List of significant changes to the DBI

Changes in DBI 1.633 - 11th Jan 2015

Fixed selectrow_*ref to return undef on error in list context
instead if an empty list.
Changed t/42prof_data.t more informative
Changed $sth->{TYPE} to be NUMERIC in DBD::File drivers as per the
DBI docs. Note TYPE_NAME is now also available. [H.Merijn Brand]
Fixed compilation error on bleadperl due DEFSV no longer being an lvalue
[Dagfinn Ilmari Mannsåker]
Added docs for escaping placeholders using a backslash.
Added docs for get_info(9000) indicating ability to escape placeholders.
Added multi_ prefix for DBD::Multi (Dan Wright) and ad2_ prefix for
DBD::AnyData2

Changes in DBI 1.632 - 9th Nov 2014

Fixed risk of memory corruption with many arguments to methods
originally reported by OSCHWALD for Callbacks but may apply
to other functionality in DBI method dispatch RT#86744.
Fixed DBD::PurePerl to not set $sth->{Active} true by default
drivers are expected to set it true as needed.
Fixed DBI::DBD::SqlEngine to complain loudly when prerequite
driver_prefix is not fulfilled (RT#93204) [Jens Rehsack]
Fixed redundant sprintf argument warning RT#97062 [Reini Urban]
Fixed security issue where DBD::File drivers would open files
from folders other than specifically passed using the
f_dir attribute RT#99508 [H.Merijn Brand]
Changed delete $h->{$key} to work for keys with 'private_' prefix
per request in RT#83156. local $h->{$key} works as before.
Added security notice to DBD::Proxy and DBI::ProxyServer because they
use Storable which is insecure. Thanks to ppisar@redhat.com RT#90475
Added note to AutoInactiveDestroy docs strongly recommending that it
is enabled in all new code.

Changes in DBI 1.631 - 20th Jan 2014

NOTE: This release changes the handle passed to Callbacks from being an 'inner' handle to being an 'outer' handle. If you have code that makes use of Callbacks, ensure that you understand what this change means and review your callback code.

Changes in DBI 1.622 (svn r15327) 6th June 2012

Changes in DBI 1.621 (svn r15315) 21st May 2012

Fixed segmentation fault when a thread is created from
within another thread RT#77137, thanks to Dave Mitchell.
Updated previous Changes to credit Booking.com for sponsoring
Dave Mitchell's recent DBI optimization work.

Changes in DBI 1.612 (svn r14254) 16th July 2010

NOTE: This is a minor release for the DBI core but a major release for DBD::File and drivers that depend on it, like DBD::DBM and DBD::CSV.

This is also the first release where the bulk of the development work has been done by other people. I'd like to thank (in no particular order) Jens Rehsack, Martin J. Evans, and H.Merijn Brand for all their contributions.

Changes in DBI 1.611 (svn r13935) 29th April 2010

NOTE: minimum perl version is now 5.8.1 (as announced in DBI 1.607)
Fixed selectcol_arrayref MaxRows attribute to count rows not values
thanks to Vernon Lyon.
Fixed DBI->trace(0, *STDERR); (H.Merijn Brand)
which tried to open a file named "*main::STDERR" in perl-5.10.x
Fixes in DBD::DBM for use under threads (Jens Rehsack)
Changed "Issuing rollback() due to DESTROY without explicit disconnect"
warning to not be issued if ReadOnly set for that dbh.
Added f_lock and f_encoding support to DBD::File (H.Merijn Brand)
Added ChildCallbacks => { ... } to Callbacks as a way to
specify Callbacks for child handles.
With tests added by David E. Wheeler.
Added DBI::sql_type_cast($value, $type, $flags) to cast a string value
to an SQL type. e.g. SQL_INTEGER effectively does $value += 0;
Has other options plus an internal interface for drivers.
Documentation changes:
Small fixes in the documentation of DBD::DBM (H.Merijn Brand)
Documented specification of type casting behaviour for bind_col()
based on DBI::sql_type_cast() and two new bind_col attributes
StrictlyTyped and DiscardString. Thanks to Martin Evans.
Document fetchrow_hashref() behaviour for functions,
aliases and duplicate names (H.Merijn Brand)
Updated DBI::Profile and DBD::File docs to fix pod nits
thanks to Frank Wiegand.
Corrected typos in Gopher documentation reported by Jan Krynicky.
Documented the Callbacks attribute thanks to David E. Wheeler.
Corrected the Timeout examples as per rt 50621 (Martin J. Evans).
Removed some internal broken links in the pod (Martin J. Evans)
Added Note to column_info for drivers which do not
support it (Martin J. Evans)
Updated dbipport.h to Devel::PPPort 3.19 (H.Merijn Brand)

Changes in DBI 1.608 (svn r12742) 5th May 2009

Fixes to DBD::File (H.Merijn Brand)
bind_param () now honors the attribute argument
added f_ext attribute
File::Spec is always required. (CORE since 5.00405)
Fail and set errstr on parameter count mismatch in execute ()
Fixed two small memory leaks when running in mod_perl
one in DBI->connect and one in DBI::Gofer::Execute.
Both due to "local $ENV{...};" leaking memory.
Fixed DBD_ATTRIB_DELETE macro for driver authors
and updated DBI::DBD docs thanks to Martin J. Evans.
Fixed 64bit issues in trace messages thanks to Charles Jardine.
Fixed FETCH_many() method to work with drivers that incorrectly return
an empty list from $h->FETCH. Affected gofer.
Added 'sqlite_' as registered prefix for DBD::SQLite.
Corrected many typos in DBI docs thanks to Martin J. Evans.
Improved DBI::DBD docs thanks to H.Merijn Brand.

Changes in DBI 1.607 (svn r11571) 22nd July 2008

NOTE: Perl 5.8.1 is now the minimum supported version.
If you need support for earlier versions send me a patch.
Fixed missing import of carp in DBI::Gofer::Execute.
Added note to docs about effect of execute(@empty_array).
Clarified docs for ReadOnly thanks to Martin Evans.

Changes in DBI 1.605 (svn r11434) 16th June 2008

Fixed broken DBIS macro with threads on big-endian machines
with 64bit ints but 32bit pointers. Ticket #32309.
Fixed the selectall_arrayref, selectrow_arrayref, and selectrow_array
methods that get embedded into compiled drivers to use the
inner sth handle when passed a $sth instead of an sql string.
Drivers will need to be recompiled to pick up this change.
Fixed leak in neat() for some kinds of values thanks to Rudolf Lippan.
Fixed DBI::PurePerl neat() to behave more like XS neat().
Increased default $DBI::neat_maxlen from 400 to 1000.
Increased timeout on tests to accommodate very slow systems.
Changed behaviour of trace levels 1..4 to show less information
at lower levels.
Changed the format of the key used for $h->{CachedKids}
(which is undocumented so you shouldn't depend on it anyway)
Changed gofer error handling to avoid duplicate error text in errstr.
Clarified docs re ":N" style placeholders.
Improved gofer retry-on-error logic and refactored to aid subclassing.
Improved gofer trace output in assorted ways.
Removed the beeps "\a" from Makefile.PL warnings.
Removed check for PlRPC-modules from Makefile.PL
Added sorting of ParamValues reported by ShowErrorStatement
thanks to to Rudolf Lippan.
Added cache miss trace message to DBD::Gofer transport class.
Added $drh->dbixs_revision method.
Added explicit LICENSE specification (perl) to META.yaml

Changes in DBI 1.601 (svn rev 10103), 21st October 2007

Fixed t/05thrclone.t to work with Test::More >= 0.71
thanks to Jerry D. Hedden and Michael G Schwern.
Fixed DBI for VMS thanks to Peter (Stig) Edwards.
Added client-side caching to DBD::Gofer. Can use any cache with
get($k)/set($k,$v) methods, including all the Cache and Cache::Cache
distribution modules plus Cache::Memcached, Cache::FastMmap etc.
Works for all transports. Overridable per handle.
Added DBI::Util::CacheMemory for use with DBD::Gofer caching.
It's a very fast and small strict subset of Cache::Memory.

Changes in DBI 1.58 (svn rev 9678), 25th June 2007

Fixed code triggering fatal error in bleadperl, thanks to Steve Hay.
Fixed compiler warning thanks to Jerry D. Hedden.
Fixed t/40profile.t to use int(dbi_time()) for systems like Cygwin where
time() seems to be rounded not truncated from the high resolution time.
Removed dump_results() test from t/80proxy.t.

Changes in DBI 1.56 (svn rev 9660), 18th June 2007

Fixed printf arg warnings thanks to JDHEDDEN.
Fixed returning driver-private sth attributes via gofer.
Changed pod docs docs to use =head3 instead of =item
so now in html you get links to individual methods etc.
Changed default gofer retry_limit from 2 to 0.
Changed tests to workaround Math::BigInt broken versions.
Changed dbi_profile_merge() to dbi_profile_merge_nodes()
old name still works as an alias for the new one.
Removed old DBI internal sanity check that's no longer valid
causing "panic: DESTROY (dbih_clearcom)" when tracing enabled
Added DBI_GOFER_RANDOM env var that can be use to trigger random
failures and delays when executing gofer requests. Designed to help
test automatic retry on failures and timeout handling.
Added lots more docs to all the DBD::Gofer and DBI::Gofer classes.

Changes in DBI 1.55 (svn rev 9504), 4th May 2007

Fixed set_err() so HandleSetErr hook is executed reliably, if set.
Fixed accuracy of profiling when perl configured to use long doubles.
Fixed 42prof_data.t on fast systems with poor timers thanks to Malcolm Nooning.
Fixed potential corruption in selectall_arrayref and selectrow_arrayref
for compiled drivers, thanks to Rob Davies.
Rebuild your compiled drivers after installing DBI.
Changed some handle creation code from perl to C code,
to reduce handle creation cost by ~20%.
Changed internal implementation of the CachedKids attribute
so it's a normal handle attribute (and initially undef).
Changed connect_cached and prepare_cached to avoid a FETCH method call,
and thereby reduced cost by ~5% and ~30% respectively.
Changed _set_fbav to not croak when given a wrongly sized array,
it now warns and adjusts the row buffer to match.
Changed some internals to improve performance with threaded perls.
Changed DBD::NullP to be slightly more useful for testing.
Changed File::Spec prerequisite to not require a minimum version.
Changed tests to work with other DBMs thanks to ZMAN.
Changed ex/perl_dbi_nulls_test.pl to be more descriptive.
Added more functionality to the (undocumented) Callback mechanism.
Callbacks can now elect to provide a value to be returned, in which case
the method won't be called. A callback for "*" is applied to all methods
that don't have their own callback.
Added $h->{ReadOnly} attribute.
Added support for DBI Profile Path to contain refs to scalars
which will be de-ref'd for each profile sample.
Added dbilogstrip utility to edit DBI logs for diff'ing (gets installed)
Added details for SQLite 3.3 to NULL handling docs thanks to Alex Teslik.
Added take_imp_data() to DBI::PurePerl.
Gofer related changes:
Fixed gofer pipeone & stream transports to avoid risk of hanging.
Improved error handling and tracing significantly.
Added way to generate random 1-in-N failures for methods.
Added automatic retry-on-error mechanism to gofer transport base class.
Added tests to show automatic retry mechanism works a treat!
Added go_retry_hook callback hook so apps can fine-tune retry behaviour.
Added header to request and response packets for sanity checking
and to enable version skew between client and server.
Added forced_single_resultset, max_cached_sth_per_dbh and max_cached_dbh_per_drh
to gofer executor config.
Driver-private methods installed with install_method are now proxied.
No longer does a round-trip to the server for methods it knows
have not been overridden by the remote driver.
Most significant aspects of gofer behaviour are controlled by policy mechanism.
Added policy-controlled caching of results for some methods, such as schema metadata.
The connect_cached and prepare_cached methods cache on client and server.
The bind_param_array and execute_array methods are now supported.
Worked around a DBD::Sybase bind_param bug (which is fixed in DBD::Sybase 1.07)
Added goferperf.pl utility (doesn't get installed).
Many other assorted Gofer related bug fixes, enhancements and docs.
The http and mod_perl transports have been remove to their own distribution.
Client and server will need upgrading together for this release.

Changes in DBI 1.54 (svn rev 9157), 23rd February 2007

NOTE: This release includes the 'next big thing': DBD::Gofer.
Take a look!
WARNING: This version has some subtle changes in DBI internals.
It's possible, though doubtful, that some may affect your code.
I recommend some extra testing before using this release.
Or perhaps I'm just being over cautious...
Fixed type_info when called for multiple dbh thanks to Cosimo Streppone.
Fixed compile warnings in bleadperl on freebsd-6.1-release
and solaris 10g thanks to Philip M. Gollucci.
Fixed to compile for perl built with -DNO_MATHOMS thanks to Jerry D. Hedden.
Fixed to work for bleadperl (r29544) thanks to Nicholas Clark.
Users of Perl >= 5.9.5 will require DBI >= 1.54.
Fixed rare error when profiling access to $DBI::err etc tied variables.
Fixed DBI::ProfileDumper to not be affected by changes to $/ and $,
thanks to Michael Schwern.
Changed t/40profile.t to skip tests for perl < 5.8.0.
Changed setting trace file to no longer write "Trace file set" to new file.
Changed 'handle cleared whilst still active' warning for dbh
to only be given for dbh that have active sth or are not AutoCommit.
Changed take_imp_data to call finish on all Active child sth.
Changed DBI::PurePerl trace() method to be more consistent.
Changed set_err method to effectively not append to errstr if the new errstr
is the same as the current one.
Changed handle factory methods, like connect, prepare, and table_info,
to copy any error/warn/info state of the handle being returned
up into the handle the method was called on.
Changed row buffer handling to not alter NUM_OF_FIELDS if it's
inconsistent with number of elements in row buffer array.
Updated DBI::DBD docs re handling multiple result sets.
Updated DBI::DBD docs for driver authors thanks to Ammon Riley
and Dean Arnold.
Updated column_info docs to note that if a table doesn't exist
you get an sth for an empty result set and not an error.
Added new DBD::Gofer 'stateless proxy' driver and framework,
and the DBI test suite is now also executed via DBD::Gofer,
and DBD::Gofer+DBI::PurePerl, in addition to DBI::PurePerl.
Added ability for trace() to support filehandle argument,
including tracing into a string, thanks to Dean Arnold.
Added ability for drivers to implement func() method
so proxy drivers can proxy the func method itself.
Added SQL_BIGINT type code (resolved to the ODBC/JDBC value (-5))
Added $h->private_attribute_info method.

Changes in DBI 1.53 (svn rev 7995), 31st October 2006

Fixed checks for weaken to work with early 5.8.x versions
Fixed DBD::Proxy handling of some methods, including commit and rollback.
Fixed t/40profile.t to be more insensitive to long double precision.
Fixed t/40profile.t to be insensitive to small negative shifts in time
thanks to Jamie McCarthy.
Fixed t/40profile.t to skip tests for perl < 5.8.0.
Fixed to work with current 'bleadperl' (~5.9.5) thanks to Steve Peters.
Users of Perl >= 5.9.5 will require DBI >= 1.53.
Fixed to be more robust against drivers not handling multiple result
sets properly, thanks to Gisle Aas.
Added array context support to execute_array and execute_for_fetch
methods which returns executed tuples and rows affected.
Added Tie::Cache::LRU example to docs thanks to Brandon Black.

Changes in DBI 1.51 (svn rev 6475), 6th June 2006

Fixed $dbh->clone method 'signature' thanks to Jeffrey Klein.
Fixed default ping() method to return false if !$dbh->{Active}.
Fixed t/40profile.t to be insensitive to long double precision.
Fixed for perl 5.8.0's more limited weaken() function.
Fixed DBD::Proxy to not alter $@ in disconnect or AUTOLOADd methods.
Fixed bind_columns() to use return set_err(...) instead of die()
to report incorrect number of parameters, thanks to Ben Thul.
Fixed bind_col() to ignore undef as bind location, thanks to David Wheeler.
Fixed for perl 5.9.x for non-threaded builds thanks to Nicholas Clark.
Users of Perl >= 5.9.x will require DBI >= 1.51.
Fixed fetching of rows as hash refs to preserve utf8 on field names
from $sth->{NAME} thanks to Alexey Gaidukov.
Fixed build on Win32 (dbd_postamble) thanks to David Golden.
Improved performance for thread-enabled perls thanks to Gisle Aas.
Drivers can now use PERL_NO_GET_CONTEXT thanks to Gisle Aas.
Driver authors please read the notes in the DBI::DBD docs.
Changed DBI::Profile format to always include a percentage,
if not exiting then uses time between the first and last DBI call.
Changed DBI::ProfileData to be more forgiving of systems with
unstable clocks (where time may go backwards occasionally).
Clarified the 'Subclassing the DBI' docs.
Assorted minor changes to docs from comments on annocpan.org.
Changed Makefile.PL to avoid incompatible options for old gcc.
Added 'fetch array of hash refs' example to selectall_arrayref
docs thanks to Tom Schindl.
Added docs for $sth->{ParamArrays} thanks to Martin J. Evans.
Added reference to $DBI::neat_maxlen in TRACING section of docs.
Added ability for DBI::Profile Path to include attributes
and a summary of where the code was called from.

Changes in DBI 1.50 (svn rev 2307), 13 December 2005

Fixed Makefile.PL options for gcc bug introduced in 1.49.
Fixed handle magic order to keep DBD::Oracle happy.
Fixed selectrow_array to return empty list on error.
Changed dbi_profile_merge() to be able to recurse and merge
sub-trees of profile data.
Added documentation for dbi_profile_merge(), including how to
measure the time spent inside the DBI for an http request.

Changes in DBI 1.49 (svn rev 2287), 29th November 2005

Fixed assorted attribute handling bugs in DBD::Proxy.
Fixed croak() in DBD::NullP thanks to Sergey Skvortsov.
Fixed handling of take_imp_data() and dbi_imp_data attribute.
Fixed bugs in DBD::DBM thanks to Jeff Zucker.
Fixed bug in DBI::ProfileDumper thanks to Sam Tregar.
Fixed ping in DBD::Proxy thanks to George Campbell.
Fixed dangling ref in $sth after parent $dbh destroyed
with thanks to il@rol.ru for the bug report #13151
Fixed prerequisites to include Storable thanks to Michael Schwern.
Fixed take_imp_data to be more practical.
Change to require perl 5.6.1 (as advertised in 2003) not 5.6.0.
Changed internals to be more strictly coded thanks to Andy Lester.
Changed warning about multiple copies of Driver.xst found in @INC
to ignore duplicated directories thanks to Ed Avis.
Changed Driver.xst to enable drivers to define an dbd_st_prepare_sv
function where the statement parameter is an SV. That enables
compiled drivers to support SQL strings that are UTF-8.
Changed "use DBI" to only set $DBI::connect_via if not already set.
Changed docs to clarify pre-method clearing of err values.
Added ability for DBI::ProfileData to edit profile path on loading.
This enables aggregation of different SQL statements into the same
profile node - very handy when not using placeholders or when working
multiple separate tables for the same thing (ie logtable_2005_11_28)
Added $sth->{ParamTypes} specification thanks to Dean Arnold.
Added $h->{Callbacks} attribute to enable code hooks to be invoked
when certain methods are called. For example:
$dbh->{Callbacks}->{prepare} = sub { ... };
With thanks to David Wheeler for the kick start.
Added $h->{ChildHandles} (using weakrefs) thanks to Sam Tregar
I've recoded it in C so there's no significant performance impact.
Added $h->{Type} docs (returns 'dr', 'db', or 'st')
Adding trace message in DESTROY if InactiveDestroy enabled.
Added %drhs = DBI->installed_drivers();
Ported DBI::ProfileDumper::Apache to mod_perl2 RC5+
thanks to Philip M. Golluci

Changes in DBI 1.45 (svn rev 480), 6th October 2004

Changes in DBI 1.44 (svn rev 478), 5th October 2004

Fixed build issues on VMS thanks to Jakob Snoer.
Fixed DBD::File finish() method to return 1 thanks to Jan Dubois.
Fixed rare core dump during global destruction thanks to Mark Jason Dominus.
Fixed risk of utf8 flag persisting from one row to the next.
Changed bind_param_array() so it doesn't require all bind arrays
to have the same number of elements.
Changed bind_param_array() to error if placeholder number <= 0.
Changed execute_array() definition, and default implementation,
to effectively NULL-pad shorter bind arrays.
Changed execute_array() to return "0E0" for 0 as per the docs.
Changed execute_for_fetch() definition, and default implementation,
to return "0E0" for 0 like execute() and execute_array().
Changed Test::More prerequisite to Test::Simple (which is also the name
of the distribution both are packaged in) to work around ppm behaviour.
Corrected docs to say that get/set of unknown attribute generates
a warning and is no longer fatal. Thanks to Vadim.
Corrected fetchall_arrayref() docs example thanks to Drew Broadley.
Added $h1->swap_inner_handle($h2) sponsored by BizRate.com

Changes in DBI 1.43 (svn rev 377), 2nd July 2004

Fixed connect() and connect_cached() RaiseError/PrintError
which would sometimes show "(no error string)" as the error.
Fixed compiler warning thanks to Paul Marquess.
Fixed "trace level set to" trace message thanks to H.Merijn Brand.
Fixed DBD::DBM $dbh->{dbm_tables}->{...} to be keyed by the
table name not the file name thanks to Jeff Zucker.
Fixed last_insert_id(...) thanks to Rudy Lippan.
Fixed propagation of scalar/list context into proxied methods.
Fixed DBI::Profile::DESTROY to not alter $@.
Fixed DBI::ProfileDumper new() docs thanks to Michael Schwern.
Fixed _load_class to propagate $@ thanks to Drew Taylor.
Fixed compile warnings on Win32 thanks to Robert Baron.
Fixed problem building with recent versions of MakeMaker.
Fixed DBD::Sponge not to generate warning with threads.
Fixed DBI_AUTOPROXY to work more than once thanks to Steven Hirsch.
Changed TraceLevel 1 to not show recursive/nested calls.
Changed getting or setting an invalid attribute to no longer be
a fatal error but generate a warning instead.
Changed selectall_arrayref() to call finish() if
$attr->{MaxRows} is defined.
Changed all tests to use Test::More and enhanced the tests thanks
to Stevan Little and Andy Lester. See http://qa.perl.org/phalanx/
Changed Test::More minimum prerequisite version to 0.40 (2001).
Changed DBI::Profile header to include the date and time.
Added DBI->parse_dsn($dsn) method.
Added warning if build directory path contains white space.
Added docs for parse_trace_flags() and parse_trace_flag().
Removed "may change" warnings from the docs for table_info(),
primary_key_info(), and foreign_key_info() methods.

Changes in DBI 1.42 (svn rev 222), 12th March 2004

Fixed $sth->{NUM_OF_FIELDS} of non-executed statement handle
to be undef as per the docs (it was 0).
Fixed t/41prof_dump.t to work with perl5.9.1.
Fixed DBD_ATTRIB_DELETE macro thanks to Marco Paskamp.
Fixed DBI::PurePerl looks_like_number() and $DBI::rows.
Fixed ref($h)->can("foo") to not croak.
Changed attributes (NAME, TYPE etc) of non-executed statement
handle to be undef instead of triggering an error.
Changed ShowErrorStatement to apply to more $dbh methods.
Changed DBI_TRACE env var so just does this at load time:
DBI->trace(split '=', $ENV{DBI_TRACE}, 2);
Improved "invalid number of parameters" error message.
Added DBI::common as base class for DBI::db, DBD::st etc.
Moved methods common to all handles into DBI::common.
Major tracing enhancement:
Added $h->parse_trace_flags("foo|SQL|7") to map a group of
trace flags into the corresponding trace flag bits.
Added automatic calling of parse_trace_flags() if
setting the trace level to a non-numeric value:
$h->{TraceLevel}="foo|SQL|7"; $h->trace("foo|SQL|7");
DBI->connect("dbi:Driver(TraceLevel=SQL|foo):...", ...);
Currently no trace flags have been defined.
Added to, and reworked, the trace documentation.
Added dbivport.h for driver authors to use.
Major driver additions that Jeff Zucker and I have been working on:
Added DBI::SQL::Nano a 'smaller than micro' SQL parser
with an SQL::Statement compatible API. If SQL::Statement
is installed then DBI::SQL::Nano becomes an empty subclass
of SQL::Statement, unless the DBI_SQL_NANO env var is true.
Added DBD::File, modified to use DBI::SQL::Nano.
Added DBD::DBM, an SQL interface to DBM files using DBD::File.
Documentation changes:
Corrected typos in docs thanks to Steffen Goeldner.
Corrected execute_for_fetch example thanks to Dean Arnold.

Changes in DBI 1.41 (svn rev 130), 22nd February 2004

Fixed execute_for_array() so tuple_status parameter is optional
as per docs, thanks to Ed Avis.
Fixed execute_for_array() docs to say that it returns undef if
any of the execute() calls fail.
Fixed take_imp_data() test on m68k reported by Christian Hammers.
Fixed write_typeinfo_pm inconsistencies in DBI::DBD::Metadata
thanks to Andy Hassall.
Fixed $h->{TraceLevel} to not return DBI->trace trace level
which it used to if DBI->trace trace level was higher.
Changed set_err() to append to errstr, with a leading "\n" if it's
not empty, so that multiple error/warning messages are recorded.
Changed trace to limit elements dumped when an array reference is
returned from a method to the max(40, $DBI::neat_maxlen/10)
so that fetchall_arrayref(), for example, doesn't flood the trace.
Changed trace level to be a four bit integer (levels 0 thru 15)
and a set of topic flags (no topics have been assigned yet).
Changed column_info() to check argument count.
Extended bind_param() TYPE attribute specification to imply
standard formating of value, eg SQL_DATE implies 'YYYY-MM-DD'.
Added way for drivers to indicate 'success with info' or 'warning'
by setting err to "0" for warning and "" for information.
Both values are false and so don't trigger RaiseError etc.
Thanks to Steffen Goeldner for the original idea.
Added $h->{HandleSetErr} = sub { ... } to be called at the
point that an error, warn, or info state is recorded.
The code can alter the err, errstr, and state values
(e.g., to promote an error to a warning, or the reverse).
Added $h->{PrintWarn} attribute to enable printing of warnings
recorded by the driver. Defaults to same value as $^W (perl -w).
Added $h->{ErrCount} attribute, incremented whenever an error is
recorded by the driver via set_err().
Added $h->{Executed} attribute, set if do()/execute() called.
Added \%attr parameter to foreign_key_info() method.
Added ref count of inner handle to "DESTROY ignored for outer" msg.
Added Win32 build config checks to DBI::DBD thanks to Andy Hassall.
Added bind_col to Driver.xst so drivers can define their own.
Added TYPE attribute to bind_col and specified the expected
driver behaviour.
Major update to signal handling docs thanks to Lincoln Baxter.
Corrected dbiproxy usage doc thanks to Christian Hammers.
Corrected type_info_all index hash docs thanks to Steffen Goeldner.
Corrected type_info COLUMN_SIZE to chars not bytes thanks to Dean Arnold.
Corrected get_info() docs to include details of DBI::Const::GetInfoType.
Clarified that $sth->{PRECISION} is OCTET_LENGTH for char types.

Changes in DBI 1.40, 7th January 2004

Fixed handling of CachedKids when DESTROYing threaded handles.
Fixed sql_user_name() in DBI::DBD::Metadata (used by write_getinfo_pm)
to use $dbh->{Username}. Driver authors please update your code.
Changed connect_cached() when running under Apache::DBI
to route calls to Apache::DBI::connect().
Added CLONE() to DBD::Sponge and DBD::ExampleP.
Added warning when starting a new thread about any loaded driver
which does not have a CLONE() function.
Added new prepare_cache($sql, \%attr, 3) option to manage Active handles.
Added SCALE and NULLABLE support to DBD::Sponge.
Added missing execute() in fetchall_hashref docs thanks to Iain Truskett.
Added a CONTRIBUTING section to the docs with notes on creating patches.

Changes in DBI 1.39, 27th November 2003

Fixed STORE to not clear error during nested DBI call, again/better,
thanks to Tony Bowden for the report and helpful test case.
Fixed DBI dispatch to not try to use AUTOLOAD for driver methods unless
the method has been declared (as methods should be when using AUTOLOAD).
This fixes a problem when the Attribute::Handlers module is loaded.
Fixed cwd check code to use $Config{path_sep} thanks to Steve Hay.
Fixed unqualified croak() calls thanks to Steffen Goeldner.
Fixed DBD::ExampleP TYPE and PRECISION attributes thanks to Tom Lowery.
Fixed tracing of methods that only get traced at high trace levels.
The level 1 trace no longer includes nested method calls so it generally
just shows the methods the application explicitly calls.
Added line to trace log (level>=4) when err/errstr is cleared.
Updated docs for InactiveDestroy and point out where and when the
trace includes the process id.
Update DBI::DBD docs thanks to Steffen Goeldner.
Removed docs saying that the DBI->data_sources method could be
passed a $dbh. The $dbh->data_sources method should be used instead.
Added link to 'DBI recipes' thanks to Giuseppe Maxia:
http://gmax.oltrelinux.com/dbirecipes.html (note that this
is not an endorsement that the recipies are 'optimal')
Note: There is a bug in perl 5.8.2 when configured with threads
and debugging enabled (bug #24463) which causes a DBI test to fail.

Changes in DBI 1.38, 21th August 2003

NOTE: The DBI now requires perl version 5.6.0 or later.
(As per notice in DBI 1.33 released 27th February 2003)
Fixed spurious t/03handles failure on 64bit perls reported by H.Merijn Brand.
Fixed spurious t/15array failure on some perl versions thanks to Ed Avis.
Fixed build using dmake on windows thanks to Steffen Goeldner.
Fixed build on using some shells thanks to Gurusamy Sarathy.
Fixed ParamValues to only be appended to ShowErrorStatement if not empty.
Fixed $dbh->{Statement} not being writable by drivers in some cases.
Fixed occasional undef warnings on connect failures thanks to Ed Avis.
Fixed small memory leak when using $sth->{NAME..._hash}.
Fixed 64bit warnings thanks to Marian Jancar.
Fixed DBD::Proxy::db::DESTROY to not alter $@ thanks to Keith Chapman.
Fixed Makefile.PL status from WriteMakefile() thanks to Leon Brocard.
Changed "Can't set ...->{Foo}: unrecognised attribute" from an error to a
warning when running with DBI::ProxyServer to simplify upgrades.
Changed execute_array() to no longer require ArrayTupleStatus attribute.
Changed DBI->available_drivers to not hide DBD::Sponge.
Updated/moved placeholder docs to a better place thanks to Johan Vromans.
Changed dbd_db_do4 api in Driver.xst to match dbd_st_execute (return int,
not bool), relevant only to driver authors.
Changed neat(), and thus trace(), so strings marked as utf8 are presented
in double quotes instead of single quotes and are not sanitized.
Added $dbh->data_sources method.
Added $dbh->last_insert_id method.
Added $sth->execute_for_fetch($fetch_tuple_sub, \@tuple_status) method.
Added DBI->installed_versions thanks to Jeff Zucker.
Added $DBI::Profile::ON_DESTROY_DUMP variable.
Added docs for DBD::Sponge thanks to Mark Stosberg.

Changes in DBI 1.37, 15th May 2003

Fixed "Can't get dbh->{Statement}: unrecognised attribute" error in test
caused by change to perl internals in 5.8.0
Fixed to build with latest development perl (5.8.1@19525).
Fixed C code to use all ANSI declarations thanks to Steven Lembark.

Changes in DBI 1.34, 28th February 2003

Fixed DBI::DBD docs to refer to DBI::DBD::Metadata thanks to Jonathan Leffler.
Fixed dbi_time() compile using BorlandC on Windows thanks to Steffen Goeldner.
Fixed profile tests to do enough work to measure on Windows.
Fixed disconnect_all() to not be required by drivers.
Added $okay = $h->can($method_name) to check if a method exists.
Added DBD::*::*->install_method($method_name, \%attr) so driver private
methods can be 'installed' into the DBI dispatcher and no longer
need to be called using $h->func(..., $method_name).
Enhanced $dbh->clone() and documentation.
Enhanced docs to note that dbi_time(), and thus profiling, is limited
to only millisecond (seconds/1000) resolution on Windows.
Removed old DBI::Shell from distribution and added Tom Lowery's improved
version to the Bundle::DBI file.
Updated minimum version numbers for modules in Bundle::DBI.

Changes in DBI 1.33, 27th February 2003

NOTE: Future versions of the DBI *will not* support perl 5.6.0 or earlier.
: Perl 5.6.1 will be the minimum supported version.
NOTE: The "old-style" connect: DBI->connect($database, $user, $pass, $driver);
: has been deprecated for several years and will now generate a warning.
: It will be removed in a later release. Please change any old connect() calls.
Added $dbh2 = $dbh1->clone to make a new connection to the database
that is identical to the original one. clone() can be called even after
the original handle has been disconnected. See the docs for more details.
Fixed merging of profile data to not sum DBIprof_FIRST_TIME values.
Fixed unescaping of newlines in DBI::ProfileData thanks to Sam Tregar.
Fixed Taint bug with fetchrow_hashref with help from Bradley Baetz.
Fixed $dbh->{Active} for DBD::Proxy, reported by Bob Showalter.
Fixed STORE to not clear error during nested DBI call,
thanks to Tony Bowden for the report and helpful test case.
Fixed DBI::PurePerl error clearing behaviour.
Fixed dbi_time() and thus DBI::Profile on Windows thanks to Smejkal Petr.
Fixed problem that meant ShowErrorStatement could show wrong statement,
thanks to Ron Savage for the report and test case.
Changed Apache::DBI hook to check for $ENV{MOD_PERL} instead of
$ENV{GATEWAY_INTERFACE} thanks to Ask Bjoern Hansen.
No longer tries to dup trace logfp when an interpreter is being cloned.
Database handles no longer inherit shared $h->err/errstr/state storage
from their drivers, so each $dbh has it's own $h->err etc. values
and is no longer affected by calls made on other dbh's.
Now when a dbh is destroyed it's err/errstr/state values are copied
up to the driver so checking $DBI::errstr still works as expected.
Build / portability fixes:
Fixed t/40profile.t to not use Time::HiRes.
Fixed t/06attrs.t to not be locale sensitive, reported by Christian Hammers.
Fixed sgi compiler warnings, reported by Paul Blake.
Fixed build using make -j4, reported by Jonathan Leffler.
Fixed build and tests under VMS thanks to Craig A. Berry.
Documentation changes:
Documented $high_resolution_time = dbi_time() function.
Documented that bind_col() can take an attribute hash.
Clarified documentation for ParamValues attribute hash keys.
Many good DBI documentation tweaks from Jonathan Leffler,
including a major update to the DBI::DBD driver author guide.
Clarified that execute() should itself call finish() if it's
called on a statement handle that's still active.
Clarified $sth->{ParamValues}. Driver authors please note.
Removed "NEW" markers on some methods and attributes and
added text to each giving the DBI version it was added in,
if it was added after DBI 1.21 (Feb 2002).
Changes of note for authors of all drivers:
Added SQL_DATA_TYPE, SQL_DATETIME_SUB, NUM_PREC_RADIX, and
INTERVAL_PRECISION fields to docs for type_info_all. There were
already in type_info(), but type_info_all() didn't specify the
index values. Please check and update your type_info_all() code.
Added DBI::DBD::Metadata module that auto-generates your drivers
get_info and type_info_all data and code, thanks mainly to
Jonathan Leffler and Steffen Goeldner. If you've not implemented
get_info and type_info_all methods and your database has an ODBC
driver available then this will do all the hard work for you!
Drivers should no longer pass Err, Errstr, or State to _new_drh
or _new_dbh functions.
Please check that you support the slightly modified behaviour of
$sth->{ParamValues}, e.g., always return hash with keys if possible.
Changes of note for authors of compiled drivers:
Added dbd_db_login6 & dbd_st_finish3 prototypes thanks to Jonathan Leffler.
All dbd_*_*() functions implemented by drivers must have a
corresponding #define dbd_*_* <driver_prefix>_*_* otherwise
the driver may not work with a future release of the DBI.
Changes of note for authors of drivers which use Driver.xst:
Some new method hooks have been added are are enabled by
defining corresponding macros:
$drh->data_sources() - dbd_dr_data_sources
$dbh->do() - dbd_db_do4
The following methods won't be compiled into the driver unless
the corresponding macro has been #defined:
$drh->disconnect_all() - dbd_discon_all

Changes in DBI 1.32, 1st December 2002

Fixed to work with 5.005_03 thanks to Tatsuhiko Miyagawa (I've not tested it).
Reenabled taint tests (accidentally left disabled) spotted by Bradley Baetz.
Improved docs for FetchHashKeyName attribute thanks to Ian Barwick.
Fixed core dump if fetchrow_hashref given bad argument (name of attribute
with a value that wasn't an array reference), spotted by Ian Barwick.
Fixed some compiler warnings thanks to David Wheeler.
Updated Steven Hirsch's enhanced proxy work (seems I left out a bit).
Made t/40profile.t tests more reliable, reported by Randy, who is part of
the excellent CPAN testers team: http://testers.cpan.org/
(Please visit, see the valuable work they do and, ideally, join in!)

Changes in DBI 1.31, 29th November 2002

The fetchall_arrayref method, when called with a $maxrows parameter,
no longer gives an error if called again after all rows have been
fetched. This simplifies application logic when fetching in batches.
Also added batch-fetch while() loop example to the docs.
The proxy now supports non-lazy (synchronous) prepare, positioned
updates (for selects containing 'for update'), PlRPC config set
via attributes, and accurate propagation of errors, all thanks
to Steven Hirsch (plus a minor fix from Sean McMurray and doc
tweaks from Michael A Chase).
The DBI_AUTOPROXY env var can now hold the full dsn of the proxy driver
plus attributes, like "dbi:Proxy(proxy_foo=>1):host=...".
Added TaintIn & TaintOut attributes to give finer control over
tainting thanks to Bradley Baetz.
The RootClass attribute no longer ignores failure to load a module,
but also doesn't try to load a module if the class already exists,
with thanks to James FitzGibbon.
HandleError attribute works for connect failures thanks to David Wheeler.
The connect() RaiseError/PrintError message now includes the username.
Changed "last handle unknown or destroyed" warning to be a trace message.
Removed undocumented $h->event() method.
Further enhancements to DBD::PurePerl accuracy.
The CursorName attribute now defaults to undef and not an error.
DBI::Profile changes:
New DBI::ProfileDumper, DBI::ProfileDumper::Apache, and
DBI::ProfileData modules (to manage the storage and processing
of profile data), plus dbiprof program for analyzing profile
data - with many thanks to Sam Tregar.
Added $DBI::err (etc) tied variable lookup time to profile.
Added time for DESTROY method into parent handles profile (used to be ignored).
Documentation changes:
Documented $dbh = $sth->{Database} attribute.
Documented $dbh->connected(...) post-connection call when subclassing.
Updated some minor doc issues thanks to H.Merijn Brand.
Updated Makefile.PL example in DBI::DBD thanks to KAWAI,Takanori.
Fixed execute_array() example thanks to Peter van Hardenberg.
Changes for driver authors, not required but strongly recommended:
Change DBIS to DBIc_DBISTATE(imp_xxh) [or imp_dbh, imp_sth etc]
Change DBILOGFP to DBIc_LOGPIO(imp_xxh) [or imp_dbh, imp_sth etc]
Any function from which all instances of DBIS and DBILOGFP are
removed can also have dPERLINTERP removed (a good thing).
All use of the DBIh_EVENT* macros should be removed.
Major update to DBI::DBD docs thanks largely to Jonathan Leffler.
Add these key values: 'Err' => \my $err, 'Errstr' => \my $errstr,
to the hash passed to DBI::_new_dbh() in your driver source code.
That will make each $dbh have it's own $h->err and $h->errstr
values separate from other $dbh belonging to the same driver.
If you have a ::db or ::st DESTROY methods that do nothing
you can now remove them - which speeds up handle destruction.

Changes in DBI 1.29, 15th July 2002

NOTE: This release changes the specified behaviour for the
: fetchrow_array method when called in a scalar context:
: The DBI spec used to say that it would return the FIRST field.
: Which field it returns (i.e., the first or the last) is now undefined.
: This does not affect statements that only select one column, which is
: usually the case when fetchrow_array is called in a scalar context.
: FYI, this change was triggered by discovering that the fetchrow_array
: implementation in Driver.xst (used by most compiled drivers)
: didn't match the DBI specification. Rather than change the code
: to match, and risk breaking existing applications, I've changed the
: specification (that part was always of dubious value anyway).
NOTE: Future versions of the DBI may not support for perl 5.5 much longer.
: If you are still using perl 5.005_03 you should be making plans to
: upgrade to at least perl 5.6.1, or 5.8.0. Perl 5.8.0 is due to be
: released in the next week or so. (Although it's a "point 0" release,
: it is the most thoroughly tested release ever.)
Added XS/C implementations of selectrow_array, selectrow_arrayref, and
selectall_arrayref to Driver.xst. See DBI 1.26 Changes for more info.
Removed support for the old (fatally flawed) "5005" threading model.
Added support for new perl 5.8 iThreads thanks to Gerald Richter.
(Threading support and safety should still be regarded as beta
quality until further notice. But it's much better than it was.)
Updated the "Threads and Thread Safety" section of the docs.
The trace output can be sent to STDOUT instead of STDERR by using
"STDOUT" as the name of the file, i.e., $h->trace(..., "STDOUT")
Added pointer to perlreftut, perldsc, perllol, and perlboot manuals
into the intro section of the docs, suggested by Brian McCain.
Fixed DBI::Const::GetInfo::* pod docs thanks to Zack Weinberg.
Some changes to how $dbh method calls are treated by DBI::Profile:
Meta-data methods now clear $dbh->{Statement} on entry.
Some $dbh methods are now profiled as if $dbh->{Statement} was empty
(because thet're unlikely to actually relate to its contents).
Updated dbiport.h to ppport.h from perl 5.8.0.
Tested with perl 5.5.3 (vanilla, Solaris), 5.6.1 (vanilla, Solaris), and
perl 5.8.0 (RC3@17527 with iThreads & Multiplicity on Solaris and FreeBSD).

Changes in DBI 1.28, 14th June 2002

Added $sth->{ParamValues} to return a hash of the most recent
values bound to placeholders via bind_param() or execute().
Individual drivers need to be updated to support it.
Enhanced ShowErrorStatement to include ParamValues if available:
"DBD::foo::st execute failed: errstr [for statement ``...'' with params: 1='foo']"
Further enhancements to DBD::PurePerl accuracy.

Changes in DBI 1.27, 13th June 2002

Fixed missing column in C implementation of fetchall_arrayref()
thanks to Philip Molter for the prompt reporting of the problem.

Changes in DBI 1.26, 13th June 2002

Fixed t/40profile.t to work on Windows thanks to Smejkal Petr.
Fixed $h->{Profile} to return undef, not error, if not set.
Fixed DBI->available_drivers in scalar context thanks to Michael Schwern.
Added C implementations of selectrow_arrayref() and fetchall_arrayref()
in Driver.xst. All compiled drivers using Driver.xst will now be
faster making those calls. Most noticeable with fetchall_arrayref for
many rows or selectrow_arrayref with a fast query. For example, using
DBD::mysql a selectrow_arrayref for a single row using a primary key
is ~20% faster, and fetchall_arrayref for 20000 rows is twice as fast!
Drivers just need to be recompiled and reinstalled to enable it.
The fetchall_arrayref speed up only applies if $slice parameter is not used.
Added $max_rows parameter to fetchall_arrayref() to optionally limit
the number of rows returned. Can now fetch batches of rows.
Added MaxRows attribute to selectall_arrayref()
which then passes it to fetchall_arrayref().
Changed selectrow_array to make use of selectrow_arrayref.
Trace level 1 now shows first two parameters of all methods
(used to only for that for some, like prepare,execute,do etc)
Trace indicator for recursive calls (first char on trace lines)
now starts at 1 not 2.
Documented that $h->func() does not trigger RaiseError etc
so applications must explicitly check for errors.
DBI::Profile with DBI_PROFILE now shows percentage time inside DBI.
HandleError docs updated to show that handler can edit error message.
HandleError subroutine interface is now regarded as stable.

Changes in DBI 1.25, 5th June 2002

Fixed build problem on Windows and some compiler warnings.
Fixed $dbh->{Driver} and $sth->{Statement} for driver internals
These are 'inner' handles as per behaviour prior to DBI 1.16.
Further minor improvements to DBI::PurePerl accuracy.

Changes in DBI 1.24, 4th June 2002

Fixed reference loop causing a handle/memory leak
that was introduced in DBI 1.16.
Fixed DBI::Format to work with 'filehandles' from IO::Scalar
and similar modules thanks to report by Jeff Boes.
Fixed $h->func for DBI::PurePerl thanks to Jeff Zucker.
Fixed $dbh->{Name} for DBI::PurePerl thanks to Dean Arnold.
Added DBI method call profiling and benchmarking.
This is a major new addition to the DBI.
See $h->{Profile} attribute and DBI::Profile module.
For a quick trial, set the DBI_PROFILE environment variable and
run your favourite DBI script. Try it with DBI_PROFILE set to 1,
then try 2, 4, 8, 10, and -10. Have fun!
Added execute_array() and bind_param_array() documentation
with thanks to Dean Arnold.
Added notes about the DBI having not yet been tested with iThreads
(testing and patches for SvLOCK etc welcome).
Removed undocumented Handlers attribute (replaced by HandleError).
Tested with 5.5.3 and 5.8.0 RC1.

Changes in DBI 1.23, 25th May 2002

Greatly improved DBI::PurePerl in performance and accuracy.
Added more detail to DBI::PurePerl docs about what's not supported.
Fixed undef warnings from t/15array.t and DBD::Sponge.

Changes in DBI 1.22, 22nd May 2002

Added execute_array() and bind_param_array() with special thanks
to Dean Arnold. Not yet documented. See t/15array.t for examples.
All drivers now automatically support these methods.
Added DBI::PurePerl, a transparent DBI emulation for pure-perl drivers
with special thanks to Jeff Zucker. Perldoc DBI::PurePerl for details.
Added DBI::Const::GetInfo* modules thanks to Steffen Goeldner.
Added write_getinfo_pm utility to DBI::DBD thanks to Steffen Goeldner.
Added $allow_active==2 mode for prepare_cached() thanks to Stephen Clouse.
Updated DBI::Format to Revision 11.4 thanks to Tom Lowery.
Use File::Spec in Makefile.PL (helps VMS etc) thanks to Craig Berry.
Extend $h->{Warn} to commit/rollback ineffective warning thanks to Jeff Baker.
Extended t/preparse.t and removed "use Devel::Peek" thanks to Scott Hildreth.
Only copy Changes to blib/lib/Changes.pm once thanks to Jonathan Leffler.
Updated internals for modern perls thanks to Jonathan Leffler and Jeff Urlwin.
Tested with perl 5.7.3 (just using default perl config).
Documentation changes:
Added 'Catalog Methods' section to docs thanks to Steffen Goeldner.
Updated README thanks to Michael Schwern.
Clarified that driver may choose not to start new transaction until
next use of $dbh after commit/rollback.
Clarified docs for finish method.
Clarified potentials problems with prepare_cached() thanks to Stephen Clouse.

Changes in DBI 1.21, 7th February 2002

The minimum supported perl version is now 5.005_03.
Fixed DBD::Proxy support for AutoCommit thanks to Jochen Wiedmann.
Fixed DBI::ProxyServer bind_param(_inout) handing thanks to Oleg Mechtcheriakov.
Fixed DBI::ProxyServer fetch loop thanks to nobull@mail.com.
Fixed install_driver do-the-right-thing with $@ on error. It, and connect(),
will leave $@ empty on success and holding the error message on error.
Thanks to Jay Lawrence, Gavin Sherlock and others for the bug report.
Fixed fetchrow_hashref to assign columns to the hash left-to-right
so later fields with the same name overwrite earlier ones
as per DBI < 1.15, thanks to Kay Roepke.
Changed tables() to use quote_indentifier() if the driver returns a
true value for $dbh->get_info(29) # SQL_IDENTIFIER_QUOTE_CHAR
Changed ping() so it no longer triggers RaiseError/PrintError.
Changed connect() to not call $class->install_driver unless needed.
Changed DESTROY to catch fatal exceptions and append to $@.
Added ISO SQL/CLI & ODBCv3 data type definitions thanks to Steffen Goeldner.
Removed the definition of SQL_BIGINT data type constant as the value is
inconsistent between standards (ODBC=-5, SQL/CLI=25).
Added $dbh->column_info(...) thanks to Steffen Goeldner.
Added $dbh->foreign_key_info(...) thanks to Steffen Goeldner.
Added $dbh->quote_identifier(...) insipred by Simon Oliver.
Added $dbh->set_err(...) for DBD authors and DBI subclasses
(actually been there for a while, now expanded and documented).
Added $h->{HandleError} = sub { ... } addition and/or alternative
to RaiseError/PrintError. See the docs for more info.
Added $h->{TraceLevel} = N attribute to set/get trace level of handle
thus can set trace level via an (eg externally specified) DSN
using the embedded attribute syntax:
$dsn = 'dbi:DB2(PrintError=1,TraceLevel=2):dbname';
Plus, you can also now do: local($h->{TraceLevel}) = N;
(but that leaks a little memory in some versions of perl).
Added some call tree information to trace output if trace level >= 3
With thanks to Graham Barr for the stack walking code.
Added experimental undocumented $dbh->preparse(), see t/preparse.t
With thanks to Scott T. Hildreth for much of the work.
Added Fowler/Noll/Vo hash type as an option to DBI::hash().
Documentation changes:
Added DBI::Changes so now you can "perldoc DBI::Changes", yeah!
Added selectrow_arrayref & selectrow_hashref docs thanks to Doug Wilson.
Added 'Standards Reference Information' section to docs to gather
together all references to relevant on-line standards.
Added link to poop.sourceforge.net into the docs thanks to Dave Rolsky.
Added link to hyperlinked BNF for SQL92 thanks to Jeff Zucker.
Added 'Subclassing the DBI' docs thanks to Stephen Clouse, and
then changed some of them to reflect the new approach to subclassing.
Added stronger wording to description of $h->{private_*} attributes.
Added docs for DBI::hash.
Driver API changes:
Now a COPY of the DBI->connect() attributes is passed to the driver
connect() method, so it can process and delete any elements it wants.
Deleting elements reduces/avoids the explicit
$dbh->{$_} = $attr->{$_} foreach keys %$attr;
that DBI->connect does after the driver connect() method returns.

Changes in DBI 1.20, 24th August 2001

WARNING: This release contains two changes that may affect your code.
: Any code using selectall_hashref(), which was added in March 2001, WILL
: need to be changed. Any code using fetchall_arrayref() with a non-empty
: hash slice parameter may, in a few rare cases, need to be changed.
: See the change list below for more information about the changes.
: See the DBI documentation for a description of current behaviour.
Fixed memory leak thanks to Toni Andjelkovic.
Changed fetchall_arrayref({ foo=>1, ...}) specification again (sorry):
The key names of the returned hashes is identical to the letter case of
the names in the parameter hash, regardless of the L</FetchHashKeyName>
attribute. The letter case is ignored for matching.
Changed fetchall_arrayref([...]) array slice syntax specification to
clarify that the numbers in the array slice are perl index numbers
(which start at 0) and not column numbers (which start at 1).
Added { Columns=>... } and { Slice =>... } attributes to selectall_arrayref()
which is passed to fetchall_arrayref() so it can fetch hashes now.
Added a { Columns => [...] } attribute to selectcol_arrayref() so that
the list it returns can be built from more than one column per row.
Why? Consider my %hash = @{$dbh->selectcol_arrayref($sql,{ Columns=>[1,2]})}
to return id-value pairs which can be used directly to build a hash.
Added $hash_ref = $sth->fetchall_hashref( $key_field )
which returns a ref to a hash with, typically, one element per row.
$key_field is the name of the field to get the key for each row from.
The value of the hash for each row is a hash returned by fetchrow_hashref.
Changed selectall_hashref to return a hash ref (from fetchall_hashref)
and not an array of hashes as it has since DBI 1.15 (end March 2001).
WARNING: THIS CHANGE WILL BREAK ANY CODE USING selectall_hashref()!
Sorry, but I think this is an important regularization of the API.
To get previous selectall_hashref() behaviour (an array of hash refs)
change $ary_ref = $dbh->selectall_hashref( $statement, undef, @bind);
to $ary_ref = $dbh->selectall_arrayref($statement, { Columns=>{} }, @bind);
Added NAME_lc_hash, NAME_uc_hash, NAME_hash statement handle attributes.
which return a ref to a hash of field_name => field_index (0..n-1) pairs.
Fixed select_hash() example thanks to Doug Wilson.
Removed (unbundled) DBD::ADO and DBD::Multiplex from the DBI distribution.
The latest versions of those modules are available from CPAN sites.
Added $dbh->begin_work. This method causes AutoCommit to be turned
off just until the next commit() or rollback().
Driver authors: if the DBIcf_BegunWork flag is set when your commit or
rollback method is called then please turn AutoCommit on and clear the
DBIcf_BegunWork flag. If you don't then the DBI will but it'll be much
less efficient and won't handle error conditions very cleanly.
Retested on perl 5.4.4, but the DBI won't support 5.4.x much longer.
Added text to SUPPORT section of the docs:
For direct DBI and DBD::Oracle support, enhancement, and related work
I am available for consultancy on standard commercial terms.
Added text to ACKNOWLEDGEMENTS section of the docs:
Much of the DBI and DBD::Oracle was developed while I was Technical
Director (CTO) of the Paul Ingram Group (www.ig.co.uk). So I'd
especially like to thank Paul for his generosity and vision in
supporting this work for many years.

Changes in DBI 1.19, 20th July 2001

Made fetchall_arrayref({ foo=>1, ...}) be more strict to the specification
in relation to wanting hash slice keys to be lowercase names.
WARNING: If you've used fetchall_arrayref({...}) with a hash slice
that contains keys with uppercase letters then your code will break.
(As far as I recall the spec has always said don't do that.)
Fixed $sth->execute() to update $dbh->{Statement} to $sth->{Statement}.
Added row number to trace output for fetch method calls.
Trace level 1 no longer shows fetches with row>1 (to reduce output volume).
Added $h->{FetchHashKeyName} = 'NAME_lc' or 'NAME_uc' to alter
behaviour of fetchrow_hashref() method. See docs.
Added type_info quote caching to quote() method thanks to Dean Kopesky.
Makes using quote() with second data type param much much faster.
Added type_into_all() caching to type_info(), spotted by Dean Kopesky.
Added new API definition for table_info() and tables(),
driver authors please note!
Added primary_key_info() to DBI API thanks to Steffen Goeldner.
Added primary_key() to DBI API as simpler interface to primary_key_info().
Indent and other fixes for DBI::DBD doc thanks to H.Merijn Brand.
Added prepare_cached() insert_hash() example thanks to Doug Wilson.
Removed false docs for fetchall_hashref(), use fetchall_arrayref({}).

Changes in DBI 1.18, 4th June 2001

Fixed that altering ShowErrorStatement also altered AutoCommit!
Thanks to Jeff Boes for spotting that clanger.
Fixed DBD::Proxy to handle commit() and rollback(). Long overdue, sorry.
Fixed incompatibility with perl 5.004 (but no one's using that right? :)
Fixed connect_cached and prepare_cached to not be affected by the order
of elements in the attribute hash. Spotted by Mitch Helle-Morrissey.
Fixed version number of DBI::Shell
reported by Stuhlpfarrer Gerhard and others.
Defined and documented table_info() attribute semantics (ODBC compatible)
thanks to Olga Voronova, who also implemented then in DBD::Oracle.
Updated Win32::DBIODBC (Win32::ODBC emulation) thanks to Roy Lee.

Changes in DBI 1.14, 14th June 2000

NOTE: This version is the one the DBI book is based on.
NOTE: This version requires at least Perl 5.004.
Perl 5.6 ithreads changes with thanks to Doug MacEachern.
Changed trace output to use PerlIO thanks to Paul Moore.
Fixed bug in RaiseError/PrintError handling.
(% chars in the error string could cause a core dump.)
Fixed Win32 PerlEx IIS concurrency bugs thanks to Murray Nesbitt.
Major documentation polishing thanks to Linda Mui at O'Reilly.
Password parameter now shown as **** in trace output.
Added two fields to type_info and type_info_all.
Added $dsn to PrintError/RaiseError message from DBI->connect().
Changed prepare_cached() croak to carp if sth still Active.
Added prepare_cached() example to the docs.
Added further DBD::ADO enhancements from Thomas Lowery.

Changes in DBI 1.08, 12th May 1999

Much improved DBD::ADO driver thanks to Phlip Plumlee and others.
Connect now allows you to specify attribute settings within the DSN
E.g., "dbi:Driver(RaiseError=>1,Taint=>1,AutoCommit=>0):dbname"
The $h->{Taint} attribute now also enables taint checking of
arguments to almost all DBI methods.
Improved trace output in various ways.
Fixed bug where $sth->{NAME_xx} was undef in some situations.
Fixed code for MULTIPLICITY/PERL_OBJECT thanks to Alex Smishlajev.
Fixed and documented DBI->connect_cached.
Workaround for Cygwin32 build problem with help from Jong-Pork Park.
bind_columns no longer needs undef or hash ref as first parameter.

Changes in DBI 1.07, 6th May 1999

Trace output now shows contents of array refs returned by DBI.
Changed names of some result columns from type_info, type_info_all,
tables and table_info to match ODBC 3.5 / ISO/IEC standards.
Many fixes for DBD::Proxy and ProxyServer.
Fixed error reporting in install_driver.
Major enhancement to DBI::W32ODBC from Patrick Hollins.
Added $h->{Taint} to taint fetched data if tainting (perl -T).
Added code for MULTIPLICITY/PERL_OBJECT contributed by ActiveState.
Added $sth->more_results (undocumented for now).

Changes in DBI 1.06, 6th January 1999

Fixed Win32 Makefile.PL problem in 1.04 and 1.05.
Significant DBD::Proxy enhancements and fixes
including support for bind_param_inout (Jochen and I)
Added experimental DBI->connect_cached method.
Added $sth->{NAME_uc} and $sth->{NAME_lc} attributes.
Enhanced fetchrow_hashref to take an attribute name arg.

Changes in DBI 0.95, 10th August 1998

WARNING: THIS IS AN EXPERIMENTAL RELEASE!
Fixed 0.94 slip so it will build on pre-5.005 again.
Added DBI_AUTOPROXY environment variable.
Array ref returned from fetch/fetchrow_arrayref now readonly.
Improved connect error reporting by DBD::Proxy.
All trace/debug messages from DBI now go to trace file.

Changes in DBI 0.92, 3rd February 1998

Fixed per-handle memory leak (with many thanks to Irving Reid).
Added $dbh->prepare_cached() caching variant of $dbh->prepare.
Added some attributes:
$h->{Active} is the handle 'Active' (vague concept) (boolean)
$h->{Kids} e.g. number of sth's associated with a dbh
$h->{ActiveKids} number of the above which are 'Active'
$dbh->{CachedKids} ref to prepare_cached sth cache
Added support for general-purpose 'private_' attributes.
Added experimental support for subclassing the DBI: see t/subclass.t
Added SQL_ALL_TYPES to exported :sql_types.
Added dbd_dbi_dir() and dbd_dbi_arch_dir() to DBI::DBD module so that
DBD Makefile.PLs can work with the DBI installed in non-standard locations.
Fixed 'Undefined value' warning and &sv_no output from neatsvpv/trace.
Fixed small 'once per interpreter' leak.
Assorted minor documentation fixes.

Changes in DBI 0.90, 6th September 1997

Can once again be built with Perl 5.003.
The DBI class can be subclassed more easily now.
InactiveDestroy fixed for drivers using the *.xst template.
Slightly faster handle creation.
Changed prototype for dbd_*_*_attrib() to add extra param.
Note: 0.90, 0.89 and possibly some other recent versions have
a small memory leak. This will be fixed in the next release.

Changes in DBI 0.89, 25th July 1997

Minor fix to neatsvpv (mainly used for debug trace) to workaround
bug in perl where SvPV removes IOK flag from an SV.
Minor updates to the docs.

Changes in DBI 0.87, 18th July 1997

Changes in DBI 0.86, 16th July 1997

Fixed failed connect causing 'unblessed ref' and other errors.
Drivers must handle AutoCommit FETCH and STORE else DBI croaks.
Added $h->{LongReadLen} and $h->{LongTruncOk} attributes for BLOBS.
Added DBI_USER and DBI_PASS env vars. See connect docs for usage.
Added DBI->trace() to set global trace level (like per-handle $h->trace).
PERL_DBI_DEBUG env var renamed DBI_DEBUG (old name still works for now).
Updated docs, including commit, rollback, AutoCommit and Transactions sections.
Added bind_param method and execute(@bind_values) to docs.
Fixed fetchall_arrayref.
Since the DBIS structure has change the internal version numbers have also
changed (DBIXS_VERSION == 9 and DBISTATE_VERSION == 9) so drivers will have
to be recompiled. The test is also now more sensitive and the version
mismatch error message now more clear about what to do. Old drivers are
likely to core dump (this time) until recompiled for this DBI. In future
DBI/DBD version mismatch will always produce a clear error message.
Note that this DBI release contains and documents many new features
that won't appear in drivers for some time. Driver writers might like
to read perldoc DBI::DBD and comment on or apply the information given.

Changes in DBI 0.85, 25th June 1997

NOTE: New-style connect now defaults to AutoCommit mode unless
{ AutoCommit => 0 } specified in connect attributes. See the docs.
AutoCommit attribute now defined and tracked by DBI core.
Drivers should use/honour this and not implement their own.
Added pod doc changes from Andreas and Jonathan.
New DBI_DSN env var default for connect method. See docs.
Documented the func method.
Fixed "Usage: DBD::_::common::DESTROY" error.
Fixed bug which set some attributes true when there value was fetched.
Added new internal DBIc_set() macro for drivers to use.

Changes in DBI 0.82, 23rd May 1997

Added $h->{RaiseError} attribute which, if set true, causes all errors to
trigger a die(). This makes it much easier to implement robust applications
in terms of higher level eval { ... } blocks and rollbacks.
Added DBI->data_sources($driver) method for implementation by drivers.
The quote method now returns the string NULL (without quotes) for undef.
Added VMS support thanks to Dan Sugalski.
Added a 'quick start guide' to the README.
Added neatsvpv function pointer to DBIS structure to make it available for
use by drivers. A macro defines neatsvpv(sv,len) as (DBIS->neatsvpv(sv,len)).
Old XS macro SV_YES_NO changes to standard boolSV.
Since the DBIS structure has change the internal version numbers have also
changed (DBIXS_VERSION == 8 and DBISTATE_VERSION == 8) so drivers will have
to be recompiled.

Changes in DBI 0.81, 7th May 1997

Minor fix to let DBI build using less modern perls.
Fixed a suprious typo warning.

Changes in DBI 0.80, 6th May 1997

Builds with no changes on NT using perl5.003_99 (with thanks to Jeffrey Urlwin).
Automatically supports Apache::DBI (with thanks to Edmund Mergl).
DBI scripts no longer need to be modified to make use of Apache::DBI.
Added a ping method and an experimental connect_test_perf method.
Added a fetchhash and fetch_all methods.
The func method no longer pre-clears err and errstr.
Added ChopBlanks attribute (currently defaults to off, that may change).
Support for the attribute needs to be implemented by individual drivers.
Reworked tests into standard t/*.t form.
Added more pod text. Fixed assorted bugs.

Changes in DBI 0.79, 7th Apr 1997

Changes in DBI 0.78, 28th Mar 1997

Greatly extended the pod documentation in DBI.pm, including the under
used bind_columns method. Use 'perldoc DBI' to read after installing.
Fixed $h->err. Fetching an attribute value no longer resets err.
Added $h->{InactiveDestroy}, see documentation for details.
Improved debugging of cached ('quick') attribute fetches.
errstr will return err code value if there is no string value.
Added DBI/W32ODBC to the distribution. This is a pure-perl experimental
DBI emulation layer for Win32::ODBC. Note that it's unsupported, your
mileage will vary, and bug reports without fixes will probably be ignored.

Changes in DBI 0.76, 3rd Feb 1997

Changes in DBI 0.75, 27th Jan 1997

Fix problem introduced by a change in Perl5.003_XX.
Updated README and DBI.pm docs.

Changes in DBI 0.74, 14th Jan 1997

Dispatch now sets dbi_debug to the level of the current handle
(this makes tracing/debugging individual handles much easier).
The '>> DISPATCH' log line now only logged at debug >= 3 (was 2).
The $csr->NUM_OF_FIELDS attribute can be set if not >0 already.
You can log to a file using the env var PERL_DBI_DEBUG=/tmp/dbi.log.
Added a type cast needed by IRIX.
No longer sets perl_destruct_level unless debug set >= 4.
Make compatible with PerlIO and sfio.

Changes in DBI 0.69

Changes in DBI 0.68, 2 Mar 1996

Changes to suit perl5.002 and site_lib directories.
Detects old versions ahead of new in @INC.

Changes in DBI 0.67, 15 Feb 1996

Trivial change to test suite to fix a problem shown up by the
Perl5.002gamma release Test::Harness.

Changes in DBI 0.66, 29 Jan 1996

Minor changes to bring the DBI into line with 5.002 mechanisms,
specifically the xs/pm VERSION checking mechanism.
No functionality changes. One no-last-handle bug fix (rare problem).
Requires 5.002 (beta2 or later).

Changes in DBI 0.65, 23 Oct 1995

Added $DBI::state to hold SQL CLI / ODBC SQLSTATE value.
SQLSTATE "00000" (success) is returned as "" (false), all else is true.
If a driver does not explicitly initialise it (via $h->{State} or
DBIc_STATE(imp_xxh) then $DBI::state will automatically return "" if
$DBI::err is false otherwise "S1000" (general error).
As always, this is a new feature and liable to change.
The is *no longer* a default error handler!
You can add your own using push(@{$h->{Handlers}}, sub { ... })
but be aware that this interface may change (or go away).
The DBI now automatically clears $DBI::err, errstr and state before
calling most DBI methods. Previously error conditions would persist.
Added DBIh_CLEAR_ERROR(imp_xxh) macro.
DBI now EXPORT_OK's some utility functions, neat($value),
neat_list(@values) and dump_results($sth).
Slightly enhanced t/min.t minimal test script in an effort to help
narrow down the few stray core dumps that some porters still report.
Renamed readblob to blob_read (old name still works but warns).
Added default blob_copy_to_file method.
Added $sth = $dbh->tables method. This returns an $sth for a query
which has these columns: TABLE_CATALOGUE, TABLE_OWNER, TABLE_NAME,
TABLE_TYPE, REMARKS in that order. The TABLE_CATALOGUE column
should be ignored for now.

Changes in DBI 0.64, 23 Oct 1995

Fixed 'disconnect invalidates 1 associated cursor(s)' problem.
Drivers using DBIc_ACTIVE_on/off() macros should not need any changes
other than to test for DBIc_ACTIVE_KIDS() instead of DBIc_KIDS().
Fixed possible core dump in dbih_clearcom during global destruction.

Changes in DBI 0.63, 1 Sep 1995

Changes in DBI 0.62, 26 Aug 1995

Added method redirection method $h->func(..., $method_name).
This is now the official way to call private driver methods
that are not part of the DBI standard. E.g.:
@ary = $sth->func('ora_types');
It can also be used to call existing methods. Has very low cost.
$sth->bind_col columns now start from 1 (not 0) to match SQL.
$sth->bind_columns now takes a leading attribute parameter (or undef),
e.g., $sth->bind_columns($attribs, \$col1 [, \$col2 , ...]);
Added handy DBD_ATTRIBS_CHECK macro to vet attribs in XS.
Added handy DBD_ATTRIB_GET_SVP, DBD_ATTRIB_GET_BOOL and
DBD_ATTRIB_GET_IV macros for handling attributes.
Fixed STORE for NUM_OF_FIELDS and NUM_OF_PARAMS.
Added FETCH for NUM_OF_FIELDS and NUM_OF_PARAMS.
Dispatch no longer bothers to call _untie().
Faster startup via install_method/_add_dispatch changes.

Changes in DBI 0.61, 22 Aug 1995

Added $sth->bind_col($column, \$var [, \%attribs ]);
This method enables perl variable to be directly and automatically
updated when a row is fetched. It requires no driver support
(if the driver has been written to use DBIS->get_fbav).
Currently \%attribs is unused.
Added $sth->bind_columns(\$var [, \$var , ...]);
This method is a short-cut for bind_col which binds all the
columns of a query in one go (with no attributes). It also
requires no driver support.
Added $sth->bind_param($parameter, $var [, \%attribs ]);
This method enables attributes to be specified when values are
bound to placeholders. It also enables binding to occur away
from the execute method to improve execute efficiency.
The DBI does not provide a default implementation of this.
See the DBD::Oracle module for a detailed example.
The DBI now provides default implementations of both fetch and
fetchrow. Each is written in terms of the other. A driver is
expected to implement at least one of them.
More macro and assorted structure changes in DBDXS.h. Sorry!
The old dbihcom definitions have gone. All fields have macros.
The imp_xxh_t type is now used within the DBI as well as drivers.
Drivers must set DBIc_NUM_FIELDS(imp_sth) and DBIc_NUM_PARAMS(imp_sth).
test.pl includes a trivial test of bind_param and bind_columns.

Changes in DBI 0.60, 17 Aug 1995

This release has significant code changes but much less
dramatic than the previous release. The new implementors data
handling mechanism has matured significantly (don't be put off
by all the struct typedefs in DBIXS.h, there's just to make it
easier for drivers while keeping things type-safe).
The DBI now includes two new methods:
do $dbh->do($statement)
This method prepares, executes and finishes a statement. It is
designed to be used for executing one-off non-select statements
where there is no benefit in reusing a prepared statement handle.
fetch $array_ref = $sth->fetch;
This method is the new 'lowest-level' row fetching method. The
previous @row = $sth->fetchrow method now defaults to calling
the fetch method and expanding the returned array reference.
The DBI now provides fallback attribute FETCH and STORE functions
which drivers should call if they don't recognise an attribute.
THIS RELEASE IS A GOOD STARTING POINT FOR DRIVER DEVELOPERS!
Study DBIXS.h from the DBI and Oracle.xs etc from DBD::Oracle.
There will be further changes in the interface but nothing
as dramatic as these last two releases! (I hope :-)

Changes in DBI 0.59 15 Aug 1995

NOTE: THIS IS AN UNSTABLE RELEASE!
Major reworking of internal data management!
Performance improvements and memory leaks fixed.
Added a new NullP (empty) driver and a -m flag
to test.pl to help check for memory leaks.
Study DBD::Oracle version 0.21 for more details.
(Comparing parts of v0.21 with v0.20 may be useful.)